motor swap - jeep 4.0 HO??

[gtech636p]

I purchased a '48 pilothouse shell a couple months ago, and after reading everything concerning swaps and whatnot (axles, brakes, etc), I've been wondering if anyone has swapped a 4.0 into a pilothouse.

I know it seems like a bit of a waste by not going original or throwing the biggest v8 possible in the engine bay, but it is a straight 6 and it is mopar... and since swapping things from cherokees seems to be popular why not buy a totaled jeep and strip it down for the pilothouse?

I'm not looking for a show truck, just something to drive around on the weekends... reliable and fun (read no more points or carbs).

[B1B Keven]

I think it's a great idea.

2wd Cherokee or Comanche with a disc brake solid front axle.

Stroke the 4.0 to 4.9!

[gtech636p]

I've only ever driven cherokees really... and have a 4.7L stroker already. It almost seemed to fit together as I was looking at it. Most of the parts on the truck look identical to things I have sitting around from Willy and CJ projects as well.

[B1B Keven]

I've only ever driven cherokees really... and have a 4.7L stroker already. It almost seemed to fit together as I was looking at it. Most of the parts on the truck look identical to things I have sitting around from Willy and CJ projects as well.

Sounds like you need to do it!

The stroker is in an XJ?

[Rusty O'Toole]

Have you measured the length of the engine vs engine compartment? The original engine is very short for its size, even shorter than a slant 6 which is not a long engine for a six.

I suspect the Jeep engine is substantially longer, it probably will not fit without shoving it back into the firewall quite a piece.

[Apittslife]

I am not sure if I read this right? But I am going to reply:

The Jeep Cherokee is a Unibody Chassi so it will not work as a platform / frame to set your cab onto. The Body & lower chassi work as one for strenght & ridgideity (SP?).

The 6-cyl. engine needs to be set back into the firewall on the pilothouse cab, But I think it would be a great swap, & did think about doing the same with mine.

If you just have a cab, & want to keep it Chrysler/Dodge? The Dodge Dakota is a good frame swap.

Good luck, & Hope you enjoy your project.

[Dan Babb]

If the Jeep motor is fuel injected, you'll probably want to do a wire diet on the harness. Pull the jeep engine and the full wiring harness and then with all the schematics, take out the circuits that you don't need.

It's not fun (I did it back in 2003 when I was putting a 1993 Mustang motor into a Cobra replica).

Probably pull the transmission and use it too (if it's a 2 wheel drive model). There's a chance that the computer gets a signal from the transmission to determine vehicle speed.

Sounds like a cool project.

[Scruffy49]

Go over to the www.sweptline.org website. In the member build threads is a 48 Panel being built by Slick (he's on this site too). Look at the firewall mods, he used a wheelbarrow as the donor metal... perfect shape. Or hit him up to post the build thread over on this site as well. Which he probably won't since it is a bagged, notched, IFS lowrider. You may have to join the Sweptline site to access the build threads section. Well worth it.

[Flatie46]

I drove an '88 cherokee for years, up to 340,000 miles. It was an H.0 engine and had plenty of pep. It would really light the tires up on the jeep with the 3:54 gear. If I remember correctly it would get pretty much 16mpg. I think the cherokee was pretty heavy something like 4500lbs so you may gain mileage and some quickness since I'm sure the truck is much lighter and not 4wd. If I'm not mistaken that engine design won an engineering award.

[Merle Coggins]

I think it would be an interesting project, but as Rusty said, the Jeep engine is considerably longer. You'll likely have to recess the firewall and/or push the radiator forward to gain room. Nothing is impossible with the right ambition and skill.

Merle

[Jeff Balazs]

I like the idea of an inline 6 swap or installation for a PH. Not sure about frame longevity of a V8 into stock frame swap........but a straight 6 ought to be just fine. When properly set up and tuned there is almost no vibration. Plenty of usable power too. We used a couple of Cherokees as survey vehicles back in the 90's and the engines themselves were almost flawless.

I know my taste in vehicles is not the same as a lot of members here...but.

I had an Uncle who was an aircraft mechanic who had a couple of late 60's Pontiac Tempests with the OHC 6 option. Those engines ran as smooth as a turbine. With the right bits real sleepers too..... might make for a really cool swap? I know it isn't mopar.......but those engines had carbs and do not require any electronics.

Jeff

[Rusty O'Toole]

If I wanted to put in a newer 6 I would use the 3.9 V6 out of a pickup. Much easier, and an excellent engine, like a 318 with 2 less cylinders.

[B1B Keven]

If I wanted to put in a newer 6 I would use the 3.9 V6 out of a pickup. Much easier' date=' and an excellent engine, like a 318 with 2 less cylinders.[/quote']

3.9 is a boat anchor. I owned a '90 Dakota. No power, crappy fuel mileage.

[Plymouthy Adams]

there is a dog at every race track..my 90 Dakota 3.9 was very responsive and excellent on fuel...still in the family since new...still running strong..

[Scruffy49]

Slick's 48 Panel firewall with modification by wheelbarrow tub donor metal. Set up for a small block V8 but with a bigger wheelbarrow who knows how wild you could go.

Went and got the pic because Slick isn't over here very often.

[JBNeal]

Dad had an '87 Dakota with that carbureted 3.9, and it was a slug that got 13 mpg...he liked the size of the Dakota, but that V6 performance was atrocious, and that Dodge was traded in within a year. I had a '90 Ramcharger with a 318, and it was a slug as well. I did some investigating and ended up advancing the distributor, probably 5 degrees...WOW did that thing come alive, lots of power, gas mileage went up to 20 on the highway. I had a '92 Dakota longbed with the MPFI V6, and it was fun to drive, lots of low-end torque, got 22 mpg on the highway. I ended up trading that truck for a '92 CTD; it was a solid work truck, but not as fun to drive as that Dakota longbed. IMO, stay away from most Chrysler motors with smog pumps attached, cuz they are gutless gas hogs. The MPFI V6 & V8s are more powerful & more efficient, and there's a lot of'm out there to choose from

[Young Ed]

My daily driver is a 94 dakota with the 3.9 and a 5spd with 209K miles. With mixed driving to work I get around 19mpg in the summer. Drops to about 17 in the cold. Its no sports car but its not slow either. Back when I was first driving a buddy had a golf with a bunch of custom engine mods and he couldn't take me from red light to red light.

[Young Ed]

I went looking on google this is what I could find for the measurement of a 4L motor:

32 long (without a fan) 26" high (deep part of oil pan to top of the oil fill cap) 26" wide...... 25" wide without AC 23" if you move the PS resivor.

Now it says without a fan but I'm assuming that included the water pump(site didnt say). So a 23" engine plus water pump means you've got maybe 5 inches to make room for. A challenge but probably not a deal breaker.

[Flatie46]

I've heard different stories on the 3.9. I work with a guy who bought one new ( in a Dakota ) and has always praised it for power and pep. Anthor guy told me a different story with his. Could it be maybe the gearing, maybe they respond better to the manual trans or how the engine was run in when new?

[JBNeal]

there were three different versions of the motor: carbureted ('87-'88), single point (throttle body) fuel injection ('89-'91), and mulit-point fuel injection ('92-up). The carb units were a li'l weak, the SPFI units were a li'l more powerful & more reliable, and the Magnum MPFI ran circles around the other two. Gearing would make a difference as with any engine, but the fuel delivery & aspiration were where the big improvements were made in hp & torque for this V6.

[Plymouthy Adams]

yes and its technology is old hat compared to the newer 3.7 that replaced it..

[Robert Horne]

I just brought home a 2WD/automatic Cherokee 1998 for a donor/parts vehicle.

Has been rolled over. Runs good. Just an experiment, not sure

what I will do with it.....

[gtech636p]

Pretty much what I was thinking. I know I want the rear axle, transmission, motor, wiring harness, master cylinder, etc... so why not buy a complete "totaled" cherokee to work with.

As for distances, I got a quick measurement before taking the cab off the frame yesterday. From the non-indented part of the firewall to radiator core support I got 30.25". The cherokee engine bay measured something on the order of 33.5" from rear indent in the firewall to the core support. Seems completely doable, but I've got a bit of work to do before knowing how much trouble it really will be.

[B1B Keven]

Pretty much what I was thinking. I know I want the rear axle, transmission, motor, wiring harness, master cylinder, etc... so why not buy a complete "totaled" cherokee to work with.

As for distances, I got a quick measurement before taking the cab off the frame yesterday. From the non-indented part of the firewall to radiator core support I got 30.25". The cherokee engine bay measured something on the order of 33.5" from rear indent in the firewall to the core support. Seems completely doable, but I've got a bit of work to do before knowing how much trouble it really will be.

What part of the country are you located?

Have you heard of NAXJA ?

[Robert Horne]

Pretty much what I was thinking. I know I want the rear axle, transmission, motor, wiring harness, master cylinder, etc... so why not buy a complete "totaled" cherokee to work with.

As for distances, I got a quick measurement before taking the cab off the frame yesterday. From the non-indented part of the firewall to radiator core support I got 30.25". The cherokee engine bay measured something on the order of 33.5" from rear indent in the firewall to the core support. Seems completely doable, but I've got a bit of work to do before knowing how much trouble it really will be.

I did a quick measurement today also, measurements close to yours.

With the Jeep 33 inch or so with the fan. If the fan was taken off, that would shorten the lengh a couple of inchs. Put the electric fan in the front of the radiator to push air.